Tanning process



Patented May 9, 1933- UNITED STATES PATENT OFFICE JOSEPH V. CHAPOT, OF HILLSIDE, AND RALPH E. PORTER, OF NEWARK, NEW JERSEY, ASSIGNORS TO NATIONAL OIL PRODUCTS COMPANY, OF HARRISON, NEW JERSEY, A.

CORPORATION OF NEW JERSEY TAN N IN G PROCESS No Drawing.

Our invention relates to processes for tanning leather and refers particularly to oil tanning processes.

Among the objectionable features of the present em loyed processes for the oil tanning of leat er, may be mentioned the length of time necessary for proper-tanning; excessive oxidation of the skin surface compared with the oxidation of the interior, resulting in glazing; the large amount of oil required; the many operations; the extensive equipment and the many repeated handlings of the skins.

Our invent-ion overcomes all of the above mentioned and other, objectionable features of the present employed methods for oil tanning leather and presents a new and useful method whereby the tanning process can be accomplished in a greatly reduced period of time while producing more uniform and more completely penetrated oxidizing effects.

We have found that superior results can be obtained in a greatly reduced period of time over the present employed oil tanning methods by using a tanning liquor containing a fish oil and a sulphonated fish oil especially in the presence of an oxidizing agent and an oxygen carrier, the addition of a mineral oil and formaldehyde being at times advantageous. I p

The sulphonated fish oil has greater penetrating properties than has the raw fish oil and thus carries some of the fish oil into the hide, or skin, producing a more uniformtreatment and causing a correspondingly more uniform tanning effect upon both the surface and the interior, than can be produced in the absence of a sulphonated oil, or other penetrating carrier of the fish oil employed.

We have found that the time employed in the tanning process can be very materially reduced if a suitable oxidizing a ent be used in the tanning liquor, such oxi izing agent being one which is in solution during the operation and is carried into the hide or skin thus presenting both the surface and the-in terior of the hide, or skin, to a similar oxidizing elfect.

We have further found that still more valuable results can be obtained if there be employed an oxygen carrier which will penetrate Application filed March 7,

the hide, or skin, during the tanning process.

We have further found that improved results can be obtained by the employment of {)mtripral oils or formaldehyde in the tanning It will be noted that the value of all of the above mentioned chemicals is based upon the increased penetration of the tanning materials, in order that th interior and the exterior of the hides, or skins may be subjected to practically the same tanning action at the same time, thus reducing the period of tanmng operation, and producing a practically uniform tanning effect upon both the surface and 1nter1or of the tanned materials.

Our process is adaptable for tanning all kinds of skins, but is particularly suitable and advantageous in the tanning of wool skins; full grain goat, sheep, calf and cabretta skms; flesh splits for chamois, and all types of fur skins.

Among the sulphonated oils which we have found particularly suitable in our process are sulphonated sperm oil, sulphonated cod oil,

and sulphonated sardine oil, but we do not limit ourselves to these particularly mentioned sulphated oils.

- Fish oils, having a tanning effect ma be employed among which are cod, sar ine, sperm and menhaden.

Both water soluble and oil soluble oxidizmg agents may be employed among which are sodium bichromate, potassium bichromate, sodlum perborate, ammonium salts of b chromates and perborates, sodium nitrate, nitric acid, benzoyl peroxide, peroxides and acetic peroxide.

Among the oxygen carriers suitable in our process are turpentine and kerosene particularly'the crude forms of those r uots.

any skins contain diflicult y-oxidizable oils and fats, and as hydrocarbon oils or -mineral oils, such as paraffin oil and white to higher temperatures and is particularly useful for grain leather tanning.

The following are given as examples of our process. 4

Example 1.The skins are pickled,

washed and dehydrated in any well known 1 manner and then introduced into a drum contaming a tanning liquor containing Per cent and the drum is run for from 1 to 2 hours. Skins must be examined after 1 hours to determine if excessive heatin has developed, or if knotting or balling up has taken place. Dump skins on floor or throw on truck and let lay for remainder of day and overnight. Next morning throw skins back in drum and run hour. Then run into .drum the following mixture 2 oz. mixture of above ingredients, 1 oz. 30 B. soda ash 124% Na cO and run for -1 hour longer. If no heat has developed, run

skins 15 minutes more, or longer, and until all skins have absorbed oil uniformly. Dump skins and horse up in small piles, and let lay for remainder of day and overnight. Hang up in hot rooms or drying tunnel for oxidation. Raise heat slowly to not less than 100 F. and not, more than 115 F. Even as high as 100% relative humidity will produce excellent results. Proper control of heat and humidity is .very important. Under ideal conditions a minimum of about 5 hours is necessary for complete oxidation, which can only be judged by examination of skins. The skins should be apparentl dry and no appreciable wet oil spots shoul be .visible at the time the skins are taken down from the 'hot rooms or tunnels. Put skins in drum and start runnin then run 'in soda ash solution made up as ollows For each dozen of average weight skins use 3 gals of water in WhlCh is dissolved A lb. of soda ash 58%) at about 105 F. temperature: Run rum for 20 minutes then run in soap solution made up as follows For each dozen of average weight skins use 3 gals of water in which is dissolved ,4 lb. of soap Run drum for 20 min.

longer. Then put on screen door and run drum until most of soap and soda solution has been removed. Then start flow of lukewarm water through gudgeon and rinse thoroughly. Dump skins and horse up. 1

Ewa/mple 2.Same as Example 1, except substitute sodium nitrate-for sodium bichromate.

. -Ewa-mple Ii-Same as Example 1, except substitute glycerine for formaldehyde.

Per cent Raw fish oil L 46 Sulphonated cod oil 5O Oleic acid 4 Emmnple 8.-The following treating solution is employed Per cent Raw fish oil 42 It will be noted that our process presents means whereby skins and hides can be tanned in a, most thorough and economical manner With'the production of uniform results.

We do not limit ourselves to the particular materials, chemicals, quantities, proportions, temperatures or steps of procedure specifical 1y mentioned as these are given simply as a means for clearly describing our invention.

What we claim is 1. A process for tanning leather which consists in treatingleather with a tanning liquor of fish oil and a sulphonated fish oil.

2. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil and an oxidizing agent.

3. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil, an oxidizing agent and an oxygen carrier.

4. A process for tanning leather which consists in treating leather with a tanning liquor offish oil, a sulphonated fish oil, an oxidizing agent, an oxygen carrier and a mineral oil.

5. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil, an oxidizing agent, an oxygen carrier, a mineral oil and formaldehyde.

6. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil and an oxygen carrier.

7. A process fortanning leather which consists in treating leather with a tanning formaldehyde.

9. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil, an

oxidizing agent and an oxygen carrier.

' 5 10. A process for tanning leather which consists in treating leather with a tanning liquor of fish oil, a sulphonated fish oil, an oxidizing agent and a mineral oil.

11. A process for tanning eather which consists in treating leather with a tanning liquor of a fish oil, a sulphonated fish oil, an oxygen carrier and a mineral oil.

12. A process for tanning leather which consists in treating leather with a tanninlig liquor of a fish 011, a sulphonated fish o' an oxygen carrier and formaldehyde.

13. A process for tanning leather which consists in treating leather with a tanning liquor of a 'fish oil, a sulphonated fish oil, a

'20 mineral oil and formaldehyde.

Signed at Harrison, in the coimty of Hudson and State of New Jersey this 3rd day of March, 1932.

JOSEPH V. CHAPOT. RALPH E. PORTER. 

